In order to observe a minute area of an object, a scanning electron microscope (SEM), a transmission electron microscope (TEM), or the like is used. Generally, in these apparatuses, a housing is evacuated for disposing a sample, an atmosphere of the sample is in a vacuum state, and then the sample is imaged. However, a biochemical sample, a liquid sample, or the like is damaged by vacuum, or the state thereof is changed. On the other hand, since needs to want to observe are large, such a sample with the electron microscope, the SEM apparatus which is able to observe the sample to be observed under atmospheric pressure, has been strongly desired.
Therefore, in recent years, a SEM apparatus, in which a sample is able to be disposed under atmospheric pressure by partitioning to be a vacuum state and an atmospheric state by providing an electron beam permeable membrane between an electron optical system and the sample, has been disclosed. In the apparatus, in a state where the membrane and the sample do not come into contact with each other by using a sample stage disposed just below the membrane, it is possible to change a sample position and to perform SEM observation under atmospheric pressure.